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[195.135.220.15]) by mx.google.com with ESMTPS id g7si1394779ejk.311.2019.04.02.00.49.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Apr 2019 00:49:12 -0700 (PDT) Received-SPF: pass (google.com: domain of mhocko@suse.com designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of mhocko@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E4FECABF5; Tue, 2 Apr 2019 07:49:11 +0000 (UTC) Date: Tue, 2 Apr 2019 09:49:11 +0200 From: Michal Hocko To: Yafang Shao Cc: willy@infradead.org, Jan Kara , Hugh Dickins , Vlastimil Babka , Andrew Morton , Linux MM Subject: Re: [PATCH] mm: add vm event for page cache miss Message-ID: <20190402074911.GQ28293@dhcp22.suse.cz> References: <1554185720-26404-1-git-send-email-laoar.shao@gmail.com> <20190402072351.GN28293@dhcp22.suse.cz> <20190402074459.GP28293@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190402074459.GP28293@dhcp22.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000006, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 02-04-19 09:44:59, Michal Hocko wrote: > On Tue 02-04-19 15:38:02, Yafang Shao wrote: [...] > > Seems I missed this dicussion. > > Could you pls. give a reference to it? > > The long thread starts here http://lkml.kernel.org/r/nycvar.YFH.7.76.1901051817390.16954@cbobk.fhfr.pm Thinking about it some more this like falls into the same category as timing attack where you measure the read latency or even watch for major faults. The attacker would destroy the side channel by the read so the attack would be likely impractical. -- Michal Hocko SUSE Labs